WO2018025718A1

WO2018025718A1 - Precast block structure

Info

Publication number: WO2018025718A1
Application number: PCT/JP2017/027002
Authority: WO
Inventors: 哲則池部
Original assignee: 黒崎播磨株式会社
Priority date: 2016-08-04
Filing date: 2017-07-26
Publication date: 2018-02-08
Also published as: KR102052663B1; TW201809569A; JP6791677B2; KR20180118751A; TWI642889B; JP2018021726A

Abstract

The present invention is a precast block structure obtained by integrating a metal plate and a precast block, wherein the occurrence of cracking in the precast block during the manufacture or use thereof is suppressed. Thus, in the present invention, a precast block structure A comprises a metal plate 1 capable of covering an outer circumference of a metallic object to be covered 11, and a precast block 2 which is integrated with the metal plate 1 and in which a porous adiabatic aggregate having a mineral composition represented by CaO・6Al₂O₃ is blended, the precast block structure having a ratio of the thickness of the precast block 2 to the length of the metal plate 1 (precast block thickness / metal plate length) of 0.2 to 0.4 in a cross section orthogonal to the longitudinal direction of the metallic object to be covered 11.

Description

Precast block structure

[Technical Field] The present invention relates to a precast block structure for fire-proofing a metal coating object such as a water-cooled skid pipe or a furnace shell inner wall in a heat facility such as a heating furnace, in particular, where heat removal is significant.

As an example of a metal-coated object, a water-cooled skid pipe constituting a walking beam of a heating furnace will be described as an example. Conventionally, a metal stud (metal stud) is generally welded to a metal water-cooled skid pipe. By constructing a regular refractory, the water-cooled skid pipe was covered with an irregular refractory, thereby ensuring heat resistance and heat insulation. However, in this conventional technology, refractory dismantling → stud removal → skid kelen → stud welding → irregular refractory framing, pouring → curing → deframing, etc., many studs (Generally, 20 to 30 pieces / m, so several thousand pieces / furnace)), and there is a problem that it takes a lot of labor and time.

In order to solve this problem, for example, Patent Document 1 proposes a method in which a metal block is pre-formed with a metal stud provided on a metal plate and preformed on a skid pipe by welding. Further, the applicant of the present application disclosed in Patent Document 2 “a metal plate capable of covering the outer periphery of a metal coating object, a ceramic stud connected to the metal plate, and an indefinite shape held by the stud. A precast block structure including a precast block made of a refractory material, wherein the stud is connected so as to be movable with respect to the metal plate. .

In this way, according to the precast block structure in which the metal plate and the precast block are integrated, the metal object can be covered with fire by simply welding the metal plate to the outer periphery of the object to be coated. Compared to welding to the object, the workability is remarkably improved.

However, when the present inventors repeatedly tested this precast block structure, it was found that there was a problem that the precast block cracked during its manufacture or use.

Korean Published Patent No. 2001-0048087 Japanese Unexamined Patent Publication No. 2016-104899

The problem to be solved by the present invention is to prevent the precast block from cracking during manufacture or use in a precast block structure in which a metal plate and a precast block are integrated.

In order to solve the above-mentioned problems, the present inventors have focused attention on the conditions for integration of the metal plate and the precast block, and as a result, in order to suppress the occurrence of cracks in the precast block, the thickness of the precast block and the metal plate It turns out that the ratio of lengths is important.

That is, according to one aspect of the present invention, “a metal plate capable of covering the outer periphery of a metal coating target, and this metal plate is integrated with CaO · 6Al ₂ O ₃ as a mineral composition. In a precast block structure comprising a precast block containing a porous heat insulating aggregate, the thickness of the precast block and the metal in a cross section perpendicular to the longitudinal direction of the metal covering object There is provided a “precast block structure” characterized in that the ratio of plate lengths (precast block thickness / metal plate length) is 0.2 or more and 0.4 or less.

According to the present invention, in a precast block structure in which a metal plate and a precast block are integrated, it is possible to suppress cracks in the precast block during manufacture or use. Thereby, the effect of the precast block structure that the workability is remarkably improved as compared with the prior art can be exhibited practically.

It is a perspective view which shows the precast block structure which concerns on one Embodiment of this invention. It is a perspective view which shows the precast block structure which concerns on other embodiment of this invention. FIG. 3 is a perspective view showing a water-cooled skid pipe fire-coated with the precast block structure of FIGS. 1 and 2. FIG. 4 is a sectional view taken along the line II in FIG. 3. FIG. 4 is a sectional view taken along the line II-II in FIG. 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show an embodiment of the precast block structure of the present invention. FIG. 3 shows a water-cooled skid pipe fire-resistant coated with the precast block structure shown in FIGS. 1 and 2, and FIGS. 4 and 5 show the II and II-II sections of FIG. 3, respectively. .

The precast block structure A shown in FIG. 1 and the precast block structure B shown in FIG. 2 are both formed by integrating the metal plate 1 and the precast block 2. In the embodiment, a metal stud 3 is used to integrate the metal plate 1 and the precast block 2 (see FIGS. 4 and 5). However, the means for integration is not limited to this, and for example, as disclosed in Patent Document 2, it is possible to integrate using ceramic studs.

The metal plate 1 has a shape capable of covering the outer periphery of a metal coating object. Specifically, the metal plate 1 of the precast block structure A in FIG. 1 has a semicircular shape capable of covering a cylindrical skid post 11 (see FIG. 4) that is a covering object, The metal plate 1 of the precast block structure B has a partially elliptical shape capable of covering an elliptical cylindrical skid beam 12 (see FIG. 5) that is an object to be coated. On the other hand, the precast block 2 is made of an amorphous refractory material (CA6 lightweight castable) in which a porous heat insulating aggregate having a mineral composition of CaO · 6Al ₂ O ₃ is blended. This CA6 lightweight castable has features that it is lightweight, has low thermal conductivity, and is excellent in resistance to scale erosion, and can improve the heat insulation effect of the precast block structures A and B.

Using these precast block structures A and B, the water-cooled skid pipe 10 is fireproof coated as shown in FIG. Specifically, the skid post 11 of the water-cooled skid pipe 10 is fire-resistant coated using two precast block structures A in the circumferential direction as shown in FIG. At this time, the metal plate 1 is welded to the skid post 11, and this welding is easily and surely performed by using a gap provided by the end 1 a of the metal plate 1 (a gap provided for welding). can do. After welding, the gap provided by the end 1a of the metal plate 1 is filled with the patching material 4. On the other hand, the skid beam 12 of the water-cooled skid pipe 10 is fire-resistant coated using two precast block structures B in the circumferential direction as shown in FIG. At this time, the metal plate 1 is welded to the skid beam 12, and this welding can also be easily and reliably performed by utilizing the gap provided by the end 1a of the metal plate 1. The gap provided by the end portion 1a is filled with the patching material 4. Note that the gap between the precast block structures B, B adjacent in the circumferential direction is the upper part of the skid beam 12, and the upper part of the skid beam 12 is composed of the patching material 4 and is a metal skid for supporting the steel material. Buttons 13 are installed at appropriate intervals. Further, the joining portion between the skid post 11 and the skid beam 12 is also formed of the patching material 4.

In the present embodiment, a fiber (alumina fiber) containing 70 mass% or more of Al ₂ O ₃ component between the precast block structures A and A adjacent in the longitudinal direction and between the precast block structures B and B. C (see C in FIG. 3) is installed. The portion where the fiber C is installed is a so-called expansion allowance, and the CAO component in the CA6 lightweight castable reacts with the alumina component in the fiber by heating at the time of first use, and the CA2 (CaO.2Al ₂ O ₃ ) or expansion by producing CA6 (CaO.6Al ₂ O ₃ ). And CA2 and CA6 produced | generated by the said reaction show the behavior of expansion-contraction similar to CA6 lightweight castable. By these, it can suppress that a clearance gap produces at the time of use in the expansion allowance provided between adjacent precast block structures. Moreover, since the expansion allowance itself is ensured, it can also suppress that a crack and a crack arise in a precast block by the stress by thermal expansion.
In addition, you may install the fiber C between the precast block structures A and A adjacent in the circumferential direction, and between the precast book structures B and B.

In the above configuration, the precast block structures A and B of the present invention are pre-cast blocks in a cross section orthogonal to the longitudinal direction of the metal covering object (skid post 11, skid beam 12), that is, in FIGS. The ratio of the thickness of 2 and the length of the metal plate 1 (the thickness of the precast block / the length of the metal plate) is 0.2 or more and 0.4 or less. If the value of this ratio is large (the thickness of the precast block 2 is too large), the precast block 2 is liable to crack during use and the spall resistance decreases. This is presumably because the temperature gradient between the inner peripheral side and the outer peripheral side of the precast block 2 increases as the thickness of the precast block 2 increases. Moreover, since the weight of a precast block structure increases as the thickness of the precast block 2 increases, the workability decreases. Also from this point, the ratio needs to be 0.4 or less. On the other hand, if the ratio is small (the thickness of the precast block 2 is too small), the precast block 2 is likely to be cracked particularly during production due to insufficient strength.

In the present invention, the “thickness of the precast block” refers to the thickness in the direction perpendicular to the metal plate in the cross section perpendicular to the longitudinal direction of the metal object, and “the length of the metal plate”. Means the length of the metal plate along the circumferential direction of the metal coating object in a cross section orthogonal to the longitudinal direction of the metal coating object.

In the semi-cylindrical precast block structure A (hereinafter referred to as “type A”) shown in FIG. 1 and the partially elliptical precast block structure B (hereinafter referred to as “type B”) shown in FIG. About the precast block structure which changed the thickness of a precast block and the length of a metal plate as shown in 1, the presence or absence of the crack at the time of manufacture, workability, and spall resistance were evaluated. In Table 1, a precast block is simply referred to as a block.

Regarding the presence or absence of cracks at the time of production, an amorphous refractory material (CA6 lightweight castable) was kneaded with a predetermined amount of moisture and cast into the precast block shape of each example, followed by curing, de-framed, and drying steps. The evaluation was based on the presence or absence of cracks. In Table 1, “O” indicates that there is no crack, and “X” indicates that there is a crack.
The workability was evaluated by the weight of the precast block structure. In Table 1, a weight of less than 40 kg is indicated by ◯, and 40 kg or more is indicated by ×.
The spall resistance was evaluated by the presence or absence of cracks when the heating / cooling cycle in which the outer peripheral surface of the precast block structure was heated to 1300 ° C. and then forced-air cooling was repeated five times. In Table 1, “O” indicates that there is no crack, and “X” indicates that there is a crack. The evaluation of the spall resistance assumes the presence or absence of cracks during use.

As shown in Table 1, Examples 1 to 4 in which the ratio of the thickness of the precast block to the length of the metal plate (the thickness of the precast block / the length of the metal plate) is in the range of 0.2 to 0.4 ( In Type A) and Examples 5 and 6 (Type B), cracks did not occur during production, and workability and spall resistance were also good.

On the other hand, in Comparative Examples 1 and 3 (type A) and Comparative example 5 (type B) in which the ratio is less than 0.2, cracks occurred during production. Further, in Comparative Examples 2, 4 (Type A) and Comparative Example 6 (Type B) in which the ratio exceeds 0.4, it was determined that the spall resistance was poor and cracks were likely to occur in the precast block during use. In addition, it was not possible to evaluate the spall resistance for Comparative Examples 1, 3, and 5 in which cracks occurred during the production.

A, B Precast block structure C fiber (alumina fiber)
DESCRIPTION OF SYMBOLS 1 Metal plate 1a End part of metal plate 2 Precast block 3 Metal stud 4 Patching material 10 Water-cooled skid pipe 11 Skid post 12 Skid beam 13 Skid button

Claims

A metal plate capable of covering the outer periphery of a metal object,
In a precast block structure including a precast block that is integrated with the metal plate and that contains a porous heat insulating aggregate made of CaO · 6Al 2 O 3 as a mineral composition,
In a cross section perpendicular to the longitudinal direction of the metal coating object, the ratio of the thickness of the precast block to the length of the metal plate (precast block thickness / metal plate length) is 0.2 or more and 0. . Precast block structure characterized by being 4 or less.